Apparatus for plating



June 9, 1931. D@ EWING 1,808,809

APPARATUS FOR PLATING .I

Filed Oct. v5, 1927 Il: We seej 3 y ATTORNEYS. I

Patented June 9, 1931 PATENT OFFICE DWIGHT T. EWING,OF EAST LANSING, MICHIGAN ArrAnArUs ron PLATING Application led October 5, 1927. Serial No. 224,046.

The object of my invention is to provide a system of plating which may be simply and economically operated and which will last indefinitely.

Still a further object of my invention is to provide a system for plating wherein the articles 'being plated may be carried through a plating solution on a conveyor, so that the articles may be plated by what is termed a continuous process as distinguished from a job process.

Still a further object of my invention is to provide improved means for depositing a plate on articles in connection with a continuous system of plating whereby the plate may be limited to any desired portion of the surface of the article.

Still a further obj ect of my invention is to provide means for depositing plate on inside and inaccessible portions of an article in a continuous plating process.

With these and other objects in view,\my invention consists in the arrangement, combi-l nation, and construction of the various parts of my improved device, and the method of using same, as described in the specification, claimed in the claim, and illustrated in the accompanying drawings, in which:

Figure 1 shows a side elevation of a device for plating according to my improved method.

Figure 2 shows a vertical transverse sectional view to the device shown in Figure 1.

Figure 3 shows a vertical sectional View taken on the line 3-3 of Figure 2, and

Figure 4 shows a vertical central sectional enlarged view ofone of the work holders, in which the work is clamped during its progv ress through theplating solution.

Referring to the accompanying drawings, I have used the reference numeral 10 to indicate generally a rectangular plating tank of conventional form. This tank has a pair of conductors or rails 11 and mounted on the- -edges of the tank at either side thereof, which -upwardly therefrom at intervals and carrying pairs of spaced rollers 15. These rollers engage the opposite sides of the upper surfaces of the lower web of an I beam 16 which` 1s supported from the casing 12 by suitable brackets 17. This I beam 16 is so shaped that articles carried by the conveyor will be carried to position above the tank 10 and immersed in the tank and then carried up and out of the tank around to position where the conveyor may be unloaded and reloaded. The conveyor is driven by any suitable means.

The brackets 14 support a clevis 18 which extends to the conveyor chain 13 which in turn support yokes 19 which have extensions 20 at either end thereof designed to form hooksupon which the work holders may be suspended.

The exact construction and drive of this conveyor is not herein fully described and many such conveyors are standard and can practically be bought upon the open market. Any conveyor will answer for this purpose which will carry the work into and through vtion containing compounds of the material whichit is desired to use for the plate. The work forming the cathode is then connected with any suitable source of electrical energy and suspended in the plating bath. In connection with the ordinary plating bath, the anodes are a series of plates or wire which are suspended in the plating solution in any suitable manner. The work is also suspended in the solution 'and the current turned on s0 that a plate may be deposited upon the work.

When this plate has been deposited, then the work is removed from the bath by hand and other work substituted therefore. In my improved process I provide means for conveying the work to the plating bath continuously so that the plating operation lmay fit in withr other methods of continuous manufacture so that the entire article should be produced by what are termed production methods.

An anode support 24 is supported by the arm 23 and insulated therefrom by a pair of insulating plates 25 and the insulating sleeve 26. The lower plate 25 rests on a shoulder 27 formed on the shank 23 and the anode support 24 and the insulators are held from upward movement on the shank 23 by the nut 28.

This anode support consists of a long strip of relatively heavy copper which extends almost across the tank 10 and has its ends bent upon themselves at 29 to form a reinforcement for a brush mounting. The upper surface of the support 24 isnotched-at 30 so that one end of a brush fork 31 may be pivotally supported in this notch. The brush support 31 has a brush 32 at the outer end thereof and the flexible cable 33 at the inner end thereof which is designed to insure a good electrical connection between the brush V 31 and the anode support 24. The brush support 31 and the brush 32 and the end of the anode support 24 are so disposed and shaped that when the yoke 21 is hung on the conveyor and passes through the tank 10 then that the brush 32 will contact with the rail 11 at each side of the` tank 10 to conduct the anode current to the anode support 24. The anodes 34 are adjustably mounted at either end of each of the supports 24 on the studs 35 which are vertically adjustable in the' anode supports 24 by means of the nuts 51. It will be noted that each anode support 24 has an anode mounted at each end thereof.

The lower end of the arms 23 each carry a vertically adjustable movable bracket 36 which supports a work holding cup 37 at either end thereof. The cups 37 are removably secured in place by set screws 42.

A shoulder 38 is provided near the bottom of each arm 23 and below this is a pair of stop nuts 39. The bracket 36 slides up and down in the space between the shoulder 38 and the nuts 39. The arm 23 just below the shoulder 38 is square to fit a corresponding opening to arm 23 in and provided with a pin 41 which is received in a bayonet slot 50 in the arm 23 between the shoulder 38 and the nuts 39 so that the follower 40 may be slid up and down the arm 23 to lock the bracket 36 at the upper limit of its movement or to release the bracket so that it may be dropped to rest on the nuts 39.

From the construction just described it will c be operated to raise the bracket 36 to position with the work 43 adjacent to the anode 34 at which time the work holder may be hooked onto the conveyor to carry the work to the plating solution.

In the particular embodiment of my invention herein described the work is illustrated as being one half of a differential gear casing for an automobile rear axle. I desire to plate the surfaces on this gear casing vwhich I have marked with" the reference numeral 44 with chromium iii-order to harden and protect these surfaces but I do not care to have the rest `of the surface of the article plated. As a matter of fact chromium plating the `rest of the surface of the article would be avery useless expense and render subsequent machining operations more expensive. If this article were to be plated by ordinary methods, kthe inner surfaces thereof would not be coated as thickly as the outside surfaces, so that by ordinary plating methods it would be necessary to deposit an unnecessary coat ofplating on the exterior 4surface of the article many times thicker than the coating which it is desired to place on the inner surface of `the article. By my improved method, I use a shaped anode 34 which is supported in position so that the work 43 may be clamped in position surrounding the anode 34 so that practically none of the article 43 will be plated except the surfaces which I have marked 44. It will be noted\that this differential gear case half which I desire to plate is provided with three extensions 45 which have notches in their upper central surfaces 46 which are designed eventually to receive the ends of the differential spider. It is particularly important that the upper surfaces of this extension 45 and the notches 46 should not be plated with chromium as these surfaces would thereby become hardened thereby making the finishing operations more difficult and expensive. A ring 47 is provided with ribs 48 thereon whereby this ring 47 may be set-down over the casing 43 with the ribs 48 entering the notches 46 and the lower surfaces of the rin covering the upper surfaces of the extenslons 45 so that when the plating operation-is continuing, no plate will be deposited upon these upper surfaces of the extensions 45 or the surfaces of the notches 46. l

The anodes 34 are properly shaped so that the inner surfaces of these gear casings will be coated except for the surface 49 which is designed to form a bearing which lits over the end of the rear axle. There is no partiular objection to slightly hardening this surface so that a coating of chromium will be deposited thereon which will however be considerably lighter than the coating which is deposited upon the surfaces 44.

In other words by my improved method of plating I am enabled to deposit in connection with a continuous method of plating to any desired thickness at any particular surface of the article even though this surface be relatively inaccessible and I am also enabled to.

deposit different thicknesses of plate at different places on the same article and also to limit the deposit to predetermined surfaces. The advantages of such a method especially in connection with chromium plating where the plating cost is relatively high will Obvious.

In the actual practice of myv improved method, the parts set up as disclosed in the drawin s, and then the work is clamped in the wor holders and the conveyor rotated to carry the work through the plating solution to secure the desired coating on the work. When the work has passed through the solution and has been properly coated, then the conveyor carries it to position where the work holders may be unloaded and reloaded. rPhe work holders for any particular job and the anodes associated therewith are so shaped that the coating will be deposited where it is especially desired to late and not on the surfaces 'where the platlng need not or should not be.

Among the many advantages arisin from the use of my improved devicey it shou d first be pointed out that the use'of a shaped anode which moves with the work makes the difference between a successful and an unsuccessful continuous system of plating.l With a movin shaped anode, the platecan be deposite at any desired surface of the work and the amount of plate deposited can be controlled by varying the distance of the anode from the surface to be plated. Dierent thicknesses of plate can be secured when desired at different surfaces ofthe same art. Where only apart of an article need be plated or should be plated, then the costs are cut tremendousl For instance, in connectionwith the di erential gear case half housing,

the current required to plate with stationary anodes was more than three times that required to plate where a moving anode is 'beena wholly unnecessa used. Had the stationary anodes been used, it would have been necessary to go to considerable expense to remove the plate from the upper surfaces of the extensions 45 and the notches 46 therein. There would have coating on the exterior of the casin 43 o two or three times the thickness of t e coatin on the inside where this coatinglwas nee ed. It will\be understood that I ave used this differential gear half casing merely as illustrative to show that by my method of plating, I am enabled to do three things, namely, to limit the plate to a portion of the surface of the Work, to deposit plate of varying thickness at various places on the same article, and to prevent t e deposit of any plate on certain portions of the surface of the article. Of course these three advantages are all secured in connection with a contmuous system of plating and practically make such a continuous system possible. These advantages are secured by t e use of my.im roved movingfshaped anode and a plate shield suchs a ring 47.

Some chan esvmayy bev made in the construction of t e various parts of the device as illustrated, and in the method of applying plate, without depall'gtingIfromtthespirii; 1 1s.my menion dis osed in said casing and shaped so as to` fol ow the internal contour thereof, whereby the anode will be spaced a uniform distance from the inside walls ofy the casing, and

means for lowering said work holder and casing and ring from said anode `whereby the casing ma be conveniently removed from the work'hol er, said ring and notches effectivel preventing the depositing of metal on the a utting casingDsurfaces. ,Y

WIGHT T. EWING. 

